# Copyright 2012 OpenStack LLC.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
Base utilities to build API operation managers and objects on top of.
"""
import abc
import copy
import six
import six.moves.urllib.parse as urlparse
from ironicclient.common.apiclient import base
from ironicclient import exc
def getid(obj):
"""Wrapper to get object's ID.
Abstracts the common pattern of allowing both an object or an
object's ID (UUID) as a parameter when dealing with relationships.
"""
try:
return obj.id
except AttributeError:
return obj
@six.add_metaclass(abc.ABCMeta)
class Manager(object):
"""Provides CRUD operations with a particular API."""
def __init__(self, api):
self.api = api
def _path(self, resource_id=None):
"""Returns a request path for a given resource identifier.
:param resource_id: Identifier of the resource to generate the request
path.
"""
return ('/v1/%s/%s' % (self._resource_name, resource_id)
if resource_id else '/v1/%s' % self._resource_name)
@abc.abstractproperty
def resource_class(self):
"""The resource class
"""
@abc.abstractproperty
def _resource_name(self):
"""The resource name.
"""
def _get(self, resource_id, fields=None):
"""Retrieve a resource.
:param resource_id: Identifier of the resource.
:param fields: List of specific fields to be returned.
:raises exc.ValidationError: For invalid resource_id arg value.
"""
if not resource_id:
raise exc.ValidationError(
"The identifier argument is invalid. "
"Value provided: {!r}".format(resource_id))
if fields is not None:
resource_id = '%s?fields=' % resource_id
resource_id += ','.join(fields)
try:
return self._list(self._path(resource_id))[0]
except IndexError:
return None
def _get_as_dict(self, resource_id, fields=None):
"""Retrieve a resource as a dictionary
:param resource_id: Identifier of the resource.
:param fields: List of specific fields to be returned.
:returns: a dictionary representing the resource; may be empty
"""
resource = self._get(resource_id, fields=fields)
if resource:
return resource.to_dict()
else:
return {}
def _format_body_data(self, body, response_key):
if response_key:
try:
data = body[response_key]
except KeyError:
return []
else:
data = body
if not isinstance(data, list):
data = [data]
return data
def _list_pagination(self, url, response_key=None, obj_class=None,
limit=None):
"""Retrieve a list of items.
The Ironic API is configured to return a maximum number of
items per request, (see Ironic's api.max_limit option). This
iterates over the 'next' link (pagination) in the responses,
to get the number of items specified by 'limit'. If 'limit'
is None this function will continue pagination until there are
no more values to be returned.
:param url: a partial URL, e.g. '/nodes'
:param response_key: the key to be looked up in response
dictionary, e.g. 'nodes'
:param obj_class: class for constructing the returned objects.
:param limit: maximum number of items to return. If None returns
everything.
"""
if obj_class is None:
obj_class = self.resource_class
if limit is not None:
limit = int(limit)
object_list = []
object_count = 0
limit_reached = False
while url:
resp, body = self.api.json_request('GET', url)
data = self._format_body_data(body, response_key)
for obj in data:
object_list.append(obj_class(self, obj, loaded=True))
object_count += 1
if limit and object_count >= limit:
# break the for loop
limit_reached = True
break
# break the while loop and return
if limit_reached:
break
url = body.get('next')
if url:
# NOTE(lucasagomes): We need to edit the URL to remove
# the scheme and netloc
url_parts = list(urlparse.urlparse(url))
url_parts[0] = url_parts[1] = ''
url = urlparse.urlunparse(url_parts)
return object_list
def _list(self, url, response_key=None, obj_class=None, body=None):
resp, body = self.api.json_request('GET', url)
if obj_class is None:
obj_class = self.resource_class
data = self._format_body_data(body, response_key)
return [obj_class(self, res, loaded=True) for res in data if res]
def _update(self, resource_id, patch, method='PATCH'):
"""Update a resource.
:param resource_id: Resource identifier.
:param patch: New version of a given resource.
:param method: Name of the method for the request.
"""
url = self._path(resource_id)
resp, body = self.api.json_request(method, url, body=patch)
# PATCH/PUT requests may not return a body
if body:
return self.resource_class(self, body)
def _delete(self, resource_id):
"""Delete a resource.
:param resource_id: Resource identifier.
"""
self.api.raw_request('DELETE', self._path(resource_id))
@six.add_metaclass(abc.ABCMeta)
class CreateManager(Manager):
"""Provides creation operations with a particular API."""
@abc.abstractproperty
def _creation_attributes(self):
"""A list of required creation attributes for a resource type.
"""
def create(self, **kwargs):
"""Create a resource based on a kwargs dictionary of attributes.
:param kwargs: A dictionary containing the attributes of the resource
that will be created.
:raises exc.InvalidAttribute: For invalid attributes that are not
needed to create the resource.
"""
new = {}
invalid = []
for (key, value) in kwargs.items():
if key in self._creation_attributes:
new[key] = value
else:
invalid.append(key)
if invalid:
raise exc.InvalidAttribute(
'The attribute(s) "%(attrs)s" are invalid; they are not '
'needed to create %(resource)s.' %
{'resource': self._resource_name,
'attrs': '","'.join(invalid)})
url = self._path()
resp, body = self.api.json_request('POST', url, body=new)
if body:
return self.resource_class(self, body)
class Resource(base.Resource):
"""Represents a particular instance of an object (tenant, user, etc).
This is pretty much just a bag for attributes.
"""
def to_dict(self):
return copy.deepcopy(self._info)